This article describes the case of a 41-year-old woman who presented with the complaint of crepitation sound and mild pain in the left temporomandibular joint area. Panoramic radiographs taken to rule out degenerative or arthritic changes in the joints demonstrated a radiopaque mass within the left condyle. Cone beam computed tomography scans revealed an ectopic tooth located centrally within the left condyle. Thus, while considered rare, the mandibular condyle can be a possible location of an ectopic tooth.
Vacuolar-type H(+)-ATPase (V-ATPase) is a multi-subunit proton pump. The proton pump is essential for the regulation of pH in various eukaryotic cellular processes. Among the 14 subunits that constitute V-ATPase, d subunit mediates coupling between cytosolic and membrane domains. Whereas d1 is expressed ubiquitously in various types of cells, its isoform d2 is only expressed in specific cells or tissues. To characterize these isoforms, we expressed and purified the isoforms of human V-ATPase d subunits using Escherichia coli over-expression system. Subunit d1 and d2 were purified as homogeneous monomers as demonstrated by dynamic light scattering (DLS) analysis. Secondary structures of d subunits were estimated to be composed of 73% ?-helix and 2% ?-sheet, as analyzed using circular dichroism (CD) analysis. Although sequence identity and secondary structures of d subunits were highly similar, the relative stability against thermal stress was higher for d1 than d2. Efficient expression and purification of d subunits, together with biophysical and biochemical characterization, presented in this study is expected to facilitate further structural analysis to clarify specific inter-molecular interactions involved in multi-subunit assembly and regulation of H(+) transporters.
Herein, we report a simple fabrication of hybrid nanowires (NWs) composed of a p-type conjugated polymer (CP) and n-type inorganic quantum dots (QDs) by exploiting the crystallization-driven solution assembly of poly(3-hexylthiophene)-b-poly(2-vinylpyridine) (P3HT-b-P2VP) rod-coil amphiphiles. The visualization of the crystallization-driven growth evolution of hybrid NWs through systematic transmission electron microscopy experiments showed that discrete dimeric CdSe QDs bridged by P3HT-b-P2VP polymers were generated during the initial state of crystallization. These, in turn, assemble into elongated fibrils, forming the coaxial P3HT-b-P2VP/QDs hybrid NWs. In particular, the location of the QD arrays within the single strand of P3HT-b-P2VP can be controlled precisely by manipulating the regioregularity (RR) values of P3HT block and the relative lengths of P2VP block. The degree of coaxiality of the QD arrays was shown to depend on the coplanarity of the thiophene rings of P3HT block, which can be controlled by the RR value of P3HT block. In addition, the location of QDs could be regulated at the specific-local site of P3HT-b-P2VP NW according to the surface characteristics of QDs. As an example, the comparison of two different QDs coated with hydrophobic alkyl-terminated and hydroxyl-terminated molecules, respectively, is used to elucidate the effect of the surface properties of QDs on their nanolocation in the NW.
Polyamidoamine (PAMAM) is one of the widely employed non-viral vectors in gene therapy research, and shows excellent biocompatibility and relatively low cytotoxicity. However, it has poor transfection efficiency compared with that of polyethylenimine (PEI, 25kDa). To enhance the gene expression efficiency, we introduced the RRRK peptide from mouse fibroblast growth factor 3 (FGF3) to PAMAM, which is a known nuclear localization signal (NLS). We synthesized PAMAM-KRRR and PAMAM-RRRK to verify the difference of the induced functional status from reversal of the N-terminus. PAMAM containing the FGF3 peptide showed a transfection efficiency corresponding to that of PEI in HEK293, and HeLa cells, and showed much higher gene expression capacity than that of PEI in NIH3T3 cells with relatively decreased cytotoxicity. These results imply that introduction of the FGF 3 peptide has the potential to provide a novel PAMAM-based vector by enhancing its gene expression efficiency.
Single-crystalline rock-salt PbS nanowires (NWs) were synthesized using three different routes; the solvothermal, chemical vapor transport, and gas-phase substitution reaction of pregrown CdS NWs. They were uniformly grown with the  or ,  direction in a controlled manner. In the solvothermal growth, the oriented attachment of the octylamine (OA) ligands enables the NWs to be produced with a controlled morphology and growth direction. As the concentration of OA increases, the growth direction evolves from the  to the higher surface-energy  and  directions under the more thermodynamically controlled growth conditions. In the synthesis involving chemical vapor transport and the substitution reaction, the use of a lower growth temperature causes the higher surface-energy growth direction to change from  to . The high-resolution X-ray diffraction pattern and X-ray photoelectron spectroscopy results revealed that a thinner oxide-layer was produced on the surface of the PbS NWs by the substitution reaction. We fabricated field effect transistors using single PbS NW, which showed intrinsic p-type semiconductor characteristics for all three routes. For the PbS NW with a thinner oxide layer, the carrier mobility was measured to be as high as 10 cm(2) V(-1) s(-1).
We performed structure analysis of Si single crystal and CaMoO(4) inorganic crystal by energy-filtered precession electron diffraction (PED). Structure analysis was performed using conventional selected area electron diffraction, PED and energy-filtered PED (EF-PED). The EF-PED method proved to be advantageous in determining the crystal structures and accurate cell parameters of inorganic crystals due to resolution enhancement by sharpening the peak shapes and reducing inelastic scattering. Among the EF-PED methods, zero-loss PED was most useful for structure analysis by minimizing inelastic scattering intensities, while plasmon-loss PED could be used effectively to determine crystal symmetry by closely observing the conditions of forbidden reflections.
This work presents variation of oxidative catalytic activities of methanol and formic acid on Pt nanoparticles of various sizes and a comparison to the results observed on Pt(111), Pt(100), and polycrystalline Pt. The Pt nanoparticles dispersed on platelet carbon nanofiber are cuboctahedral particles, whose sizes span from 5.6 to 1.1 nm. The electrochemically active surface areas, measured using charges of hydrogen adsorption/desorption and stripping of adsorbed CO, are reasonably consistent with those calculated theoretically with a simple cuboctahedron model. However, Pt nanoparticles with extremely small size (<1.8 nm) aggregate to reduce their surface areas. The size effect of Pt nanoparticles in oxidation of methanol and formic acid is discussed in terms of specific activity (current per unit surface area) and mass activity (current per unit mass).
On the basis of Paulings first rule for ionic bonding, the coordination number of cations with oxygen anions can be determined by comparison of their relative ionic size ratio. In contrast to simple oxides, various site occupancies by multicomponent cations with similar sizes usually occur in complex oxides, resulting in distinct physical properties. Through an unprecedented combination of in situ high-temperature high-resolution electron microscopy, crystallographic image processing, geometric phase analysis, and neutron powder diffraction, we directly demonstrate that while the initial crystallites after nucleation during crystallization have a very high degree of ordering, significant local cation disordering is induced by rapid crystal growth in Li-intercalation metal-phosphate nanocrystals. The findings in this study show that control of subsequent crystal growth during coarsening is of great importance to attain a high degree of cation ordering, emphasizing the significance of atomic-level visualization in real time.
The reaction between atactic poly(2-vinylpyridine) and 1,4-dibromobutane leads to formation of long-range 3D molecular ordering in polymer chains mainly because the side group (pyridine) of the polymer chain changes to a syndotactic configuration. This may enable the production of functional molecular devices that operate on a 3D atomic scale.
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